The present invention concerns transducers of the thermostatic type which are used simultaneously to transcutaneously measure the concentration of a gas in the blood in tissue of interest, e.g., the concentration of oxygen, as well as the rate of flow of blood through the tissue of interest. Such a transducer is disclosed, for example, in Federal Republic of Germany published allowed patent application DAS No. 22 55 879.
When such transducers are being used, it is often necessary or desirable to know not merely the oxygen concentration of the blood in the tissue of interest, but also the concentration or amount of oxygen chemically bound to the blood hemoglobin per se.
Likewise, when such transducers are used, it will often be necessary or desirable to know the concentration of blood hemoglobin per se.
Of course, it will very often be necessary to know the pulse rate of the patient, and also the patient's pulse waveform, as well as the rate of blood flow through the capillaries of the tissue of interest and/or the degree of elasticity exhibited by the capillaries as blood is carried through the capillaries.